Recalled Silicone Leads Need Close Watch

Action Points

St. Jude Medical issued a medical device advisory regarding increased failure rates of Riata and Riata ST high voltage leads, and this advisory subsequently led to an FDA class I recall in December 2011.

The recalled Riata and Riata ST (Riata/ST) cardiac leads have higher electrical failure rates over the long term compared with other available leads, researchers confirmed.

The 5-year survival rate for the Riata/ST leads was 97.5%, which was significantly lower than the rates with the Sprint Quattro Secure and Endotak Reliance G/SG leads (99.2% and 99.5%, respectively, P<0.0001), according to Edmund Keung, MD, of the University of California San Francisco, and colleagues.

However, the survival rate was higher than that observed with the Sprint Fidelis lead (89.6%), which was recalled in 2009 because of the potential for lead fracture, the researchers reported online in HeartRhythm.

"Careful long-term follow-up should be maintained in patients with Riata/ST in order to prevent inappropriate shocks or failed device interventions," they wrote. "Our results ... suggest that large-scale remote monitoring may be an effective tool for continued ICD system surveillance."

Last November, St. Jude Medical issued a medical device advisory that estimated a 0.63% all-cause abrasion rate on their Riata/ST high-voltage leads. That ultimately resulted in a class I recall initiated in December, and other studies released since then have affirmed an elevated failure rate with the leads.

Keung and colleagues performed an electrical survival analysis of the Riata/ST, Quattro, Fidelis, and Endotak leads using data collected by the VA National Cardiac Device Surveillance Center, which provides remote monitoring to military veterans with implantable cardioverter-defibrillators (ICDs) and cardiac resynchronization devices across the country.

The current retrospective analysis, which was completed prior to the FDA recall, included 24,300 patients who had remote transmissions from 2002 to 2012. Leads included 1,403 Riata/ST, 6,091 Quattro, 5,072 Fidelis, and 2,401 Endotak.

Overall, there were 466 lead failures documented during the study.

The failure rates (per device-year) were as follows:

0.15% for Quattro

0.16% for Endotak

0.67% for Riata/ST

2.08% for Fidelis

The rate for Fidelis was statistically higher than for the other three lead types (P<0.0001), and the rate for Riata/ST was significantly higher than for Quattro and Endotak (P<0.0001). The difference between Quattro and Endotak was not significant.

Through 6 years, the Riata ST lead had significantly worse survival compared with the Riata lead (91.4% versus 97%, P=0.003).

The leads differed in how failure presented. More than 90% of Endotak leads presented with noise at the time of lead failure, compared with 60% of Riata/ST and 50% of Quattro leads.

Among the 47 Riata/ST failures, one patient did not have a revision, 17 underwent extraction, and 29 had new leads implanted without removing the old ones.

The strategy of abandoning the old leads without removing them "may be a viable alternative to lead extraction," according to the researchers, who noted that there were no adverse events or system malfunction possibly related to an interaction between the new and abandoned leads through an average follow-up of 18.2 months.

"Unfortunately, the structural integrity of these abandoned leads is not known, and applicability of these findings is unclear for failed leads with externalized conductors," they added.

The authors acknowledged some limitations of their analysis, including the inability to account for differences in clinical variables among patients with different lead types, the inclusion of patients enrolled in remote monitoring only, the lack of fluoroscopy data, and the uncertain generalizability of the findings beyond the mostly male veteran population.

The study was funded by the VA Health Services Research and Development Service.

Keung reported that he had no conflicts of interest. One of his co-authors reported consulting fees and honoraria from Biotronik, and research funding from Medtronic.

Reviewed by Zalman S. Agus, MD Emeritus Professor, Perelman School of Medicine at the University of Pennsylvania and Dorothy Caputo, MA, BSN, RN, Nurse Planner